Lead Poisoning

Cause

Lead poisoning is caused by eating or breathing lead-contaminated substances. Small children may get lead poisoning by licking, chewing, or eating lead-based paint on toys or woodwork such as windowsills. Small children also may be exposed by breathing, swallowing, or playing in lead-contaminated dust or soil.

Although lead poisoning can sometimes result from a single large dose of lead, it usually is caused by months or years of exposure. Because lead cannot be seen, tasted, or smelled, people usually do not know when they are being exposed. Nearly everyone has some lead in his or her body.

Before its harmful effects were realized, lead was used in most gasolines, paints, water pipes, food and drink cans, and many other products. For example, house paint made before 1950 often contained as much as 50% lead. Paint manufactured up until 1972 still contained lead. In 2000, the Canadian Mortgage Association estimated that 15% of housing in Canada was built before 1950.⁵ As many as three-quarters of houses built before 1980 may have inside walls and woodwork painted with lead-based paint.²

Environmental regulations have reduced sources of lead pollution, significantly reducing lead in paint, gasoline, plumbing systems, and food and drink cans.⁸ However, lead does not break down, so any lead already present in soil or water will stay there unless it is physically removed.

The most common sources of lead poisoning are:¹

• Lead-based paint in houses or buildings built before 1972.
• Lead-soldered pipes, which contaminate water supplies.
• Working conditions, especially in mines, metal smelters, and radiator and battery shops.
• Soil that has been contaminated with lead from smelters, hazardous waste, or gasoline.
• Hobbies that involve lead, such as stained glass or pottery.
• Alternative medicines and supplements, such as some herbs and vitamins manufactured outside of Canada or the United States.
• Cosmetics, such as facial powders made outside of Canada or the United States.
• Food that is stored in leaded crystal or in cans made with lead.
• Homemade liquor, especially in the southern United States, made in stills that are connected with lead solder. Up to 90% of this "moonshine whiskey" contains dangerous levels of lead.³

A pregnant woman who is exposed to lead can pass it to her unborn baby.⁸ Lead can also be passed to a baby through the mother's breast milk.

A recent study focusing on children in an urban primary care clinic indicates that iron-deficient children absorb greater amounts of lead than children with adequate iron intake. Though further study on the subject is required, the results suggest that increasing iron intake in high-risk populations can help decrease the amount of lead absorbed by children in these groups.⁹

Go to previous section	Go to top of page	Go to next section
Author:	Douglas Dana Sydney Youngerman-Cole, RN, BSN, RNC	Last Updated: September 26, 2006
Medical Review:	Michael J. Sexton, MD - Pediatrics Tom Bailey, MD - Family Medicine R. Steven Tharratt, MD, MPVM, FACP, FCCP - Pulmonology, Critical Care, Medical Toxicology
© 1995-2008 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.This information does not replace the advice of a doctor. Healthwise disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use. How this information was developed to help you make better health decisions.